Animal Litter, Process for Preparing Animal Litter and Method of Removal of Animal Waste

ABSTRACT

An animal litter, process for preparing the animal litter and a method for removal of animal waste using the animal litter are provided. The animal litter generally includes at least about 10 weight % finely ground pine wood powder. Further the animal litter includes a lubricant and a cohesiveness agent. The animal litter is in the form of discrete plural particles which tend to agglomerate when wetted.

RELATED APPLICATION

This application claims the benefit of prior provisional applicationSer. No. 61/600,976. The entire contents of the foregoing provisionalapplication are hereby incorporated by reference in their entireties.Also incorporated in their entireties are the disclosures of priorprovisional application Ser. Nos. 61/600,971; 61/600,966; and61/600,978.

FIELD

The present application relates to an animal litter, and moreparticularly to a litter that includes finely ground wood powder. Theapplication further pertains to a process for preparing an animallitter, methods for removal of animal waste, and related products,processes, and methods.

BACKGROUND

Clumping animal litters are typically provided in the form of discreteplural particles. The particles tend to agglomerate into solid masses orclumps when wetted by a liquid waste such as animal urine. A number ofsuch clumping litters are known. One advantage of such clumping littersis that the solid clumps, which are formed upon wetting of the litter,can be separately removed as discrete entities from the remaininglitter. The clumped litter can be discarded by the animal owner, leavingbehind a quantity of relatively uncontaminated litter for future use.Animal owners, particularly owners of house cats, often find theclumping property of such litters to be convenient for periodic cleaningof the animal litter box. Ammonia-masking properties also are desirablein animal litters because ammonia, a breakdown product of the urea foundin animal urine, is a significant factor that contributes to theundesirable odor of animal waste. Some known animal litters have goodammonia-masking properties.

Many clumping animal litters are made from clays and other mineralsubstrates. Such litters typically include particles of a mineralsubstrate, which substrate functions as an absorbent and/or odorreducer. The particles may be coated with a liquid-activated adhesivematerial, such as gelatinized starch, on the surfaces of the particles.When wetted, the adhesive material is activated and causes the discretelitter particles to agglomerate into clumps.

Although clay-based litters may be functional as clumping animallitters, such litters may have different features and characteristicscompared to other materials. For example, one feature of clay litters isthe high density of the clay component of the litter. Because of thishigh density, a relatively heavy mass of litter must be used for a givenvolume of urine. In addition, the resulting clumps of soiled litter aresomewhat heavy, and thus can fracture in the absence of stronginterparticle adhesion. Another feature of clay litters is that, becausethe clay is not biodegradable, the litter cannot be flushed into somesewage systems after use. This may be inconvenient for certain animalowners.

In recognition of these features, animal litters made from biodegradablematerials, such as seed hulls or other grain-based materials, have beenprovided. Such litters are often suitable for disposal by flushing intosewage systems. For instance, U.S. Pat. No. 6,014,947 purports todisclose a grain-based litter made from whole wheat or other groundgrains. In recognition of the features inherent in clumping animallitters, biodegradable litters that exhibit a clumping property haveundergone development. Like typical clumping clay litters, such littersoften comprise discrete particles of a liquid-absorbent substrate havinga liquid-activated adhesive coated thereon.

Numerous litters are disclosed in U.S. Pat. Nos. 7,757,638; 7,753,002;6,868,802; 6,622,658; 6,405,677; 6,216,634; and 6,098,569, as well asU.S. application Ser. No. 13/103,778, all assigned to Grain ProcessingCorporation of Muscatine, Iowa. These patents provide excellentteachings as to organic, biodegradable litters that, in preferredembodiments, are based exclusively on natural materials. The littersdisclosed in these patents have excellent ammonia absorbing properties.

The present application seeks to provide an animal litter that differsfrom the heretofore described litters.

SUMMARY

An animal litter, process for preparing the animal litter and a methodfor removal of animal waste using the animal litter are provided. Theanimal litter generally includes finely ground wood powder; in manycases, at least about 10 weight % finely ground pine wood powder.Further the animal litter includes a lubricant and a cohesiveness agent.The animal litter is in the form of discrete plural particles which tendto agglomerate when wetted. The litter may contain ground corn or corncob in addition to ground wood powder. The wood powder may be a swellingwood powder that is present in an amount effective to absorb liquid butnot so high an amount as to fracture the clump forward uponagglomeration of the litter.

Further, a process for preparing an animal litter is also provided. Theprocess includes the steps of providing a mixture of a sorbentcomprising finely ground pine wood powder, a lubricant and acohesiveness agent; and compacting the mixture of into discrete pluralcompacted particles which tend to agglomerate when wetted. The powder inmany embodiments is present in an amount of at least about 10 weight %and may have the particle size discussed above. The litter may includeground corn or corn cob in addition to wood powder.

Additionally, a method for removal of animal waste is provided. Themethod includes the steps of providing a container including an animallitter, allowing an animal to excrete waste into said litter, wherebyliquid present in said container as a result of said waste causes atleast a portion of said litter to agglomerate into at least one clump,and removing said clump from said container. The animal litter includesa sorbent comprising finely ground pine wood powder herein above, alubricant, and a cohesiveness agent. The cohesiveness agent includes astarch. The animal litter is in the form of discrete plural compactedparticles which tend to agglomerate when wetted. Further, thecohesiveness agent is present in said litter in an amount effective toenhance the intraparticle cohesion of said particles.

These and other aspects may be understood more readily from thefollowing description.

DETAILED DESCRIPTION

The animal litters described herein may be formulated as clumpinglitters or as non-clumping litters but generally is provided in the formof a clumping litter. The litter preferably is formulated to take theform of pellets or other compacted forms, particularly when the litteris intended as a cat litter.

After the litter has become soiled, the liquid in the animal urine willcause some of the litter to form a clump. The soiled litter then may beremoved from the box by removing the clump and any solid waste litterfrom remaining unsoiled litter and disposing of the soiled litter.Alternatively, the soiled litter may be removed without separating itfrom any unsoiled litter in the box, by disposing of all orsubstantially all of the litter in the box. In either case, animal wastewill be thereby removed. Optionally, the supply of litter may bereplenished with fresh litter.

A range of desired properties for clumping animal litter has beenidentified. These properties include biodegradability, high sorptioncapacity, cohesion, clumpablility, ammonia and other odor masking, adensity and texture that is acceptable for the target animal, clumpstrength, tendency to remain clumped, clump weight, and cost. Ingeneral, the various ingredients and processing conditions may beselected to accommodate a desired combination of properties. Somecombinations of ingredients and processing conditions may not yield alitter that is commercially satisfactory. Selection of appropriateingredients and processing conditions will become apparent upon reviewof the following description.

In one embodiment, the animal litter is in the form of discrete pluralparticles, which particles generally are sufficiently cohesive for useas an animal litter. By “particles” it is contemplated granules orpellets obtained by compaction. The compaction may be any processsuitable for compressing the ingredients from which the litter iscomposed to an extent that the internal cohesion of the ingredients isincreased. Generally, the mass of ingredients should become sufficientlyinternally cohesive for use as an animal litter. The preferred method ofcompaction is by pelletizing the mixtures of ingredients in a pelletmill, but other processes (such as extrusion) may be employed.Generally, the pellets formed in a pellet mill (or the extrudate formedupon extruding the litter components) should be subjected to a processsuch as crumbling, to reduce the size of the pellets (or extrudate).

In one form, the animal litter generally includes finely ground pinewood powder in combination with other materials. More specifically,finely ground pine wood powder is mixed with at least one lubricant andat least one cohesiveness agent to form the animal litter.

The finely ground wood powder is believed to function as a sorbent, anodor absorber and/or a fragrance for the litter. The finely ground woodpowder may take a variety of forms and may be included in a variety ofamounts. For example, the finely ground pine wood powder may take theform of a powder having particles that are configured to pass through a20 mesh sieve. Other forms and particle sizes of the finely ground pinewood powder may also be included in the animal litter. For example, pinewood powder material may be ground to have a larger and/or smallerparticle size and may also be included in a combination of particlesizes. In some embodiments, the wood powder is included in an amountthat is effective to absorb liquid but not so high in amount as tofracture the clump formed upon agglomeration of litter. It is believedthat the powder will swell when placed into contact with liquid. If theswelling is too great, the litter may clump but the clump may be toofriable to function adequately as a clumping animal litter. Generally,the clumps should be sufficiently cohesive to enable removal or theclump from unspoiled animal litter. The exact amount of the wood powderwill depend on a number of factors, including the overall composition ofthe product and, it is believed, the particle size distribution of thewood powder starting material.

In some embodiments, the wood particles have the following particle sizeprofile:

Over 10 Mesh 0.0-0.5 Over 20 Mesh Max. 30% Through 40 Mesh Min. 20% PanBalance

In some embodiments, the particles have the following profile:

% over % over % over % over % over % over % Thru #8 #14 #20 #30 #40 #80#80 Total Wood Flour 0.5 0.7 0.4 6.8 17.0 51.0 25.2 101 2021

The pine or other wood powder may also be included in a range ofamounts. For example, in one form, the wood powder is included such thatit forms at least about 10% of the overall animal litter composition.The wood powder may also be included in larger amounts, such as at leastabout 40%, and in some cases, at least about about 65% of the animallitter composition. In one form, the pine wood powder is included in anamount of about 10% to about 85% by weight; in some embodiments, from10-20% by weight. In some embodiments, the wood powder is included in anamount that is effective to absorb liquid but not so high in amount asto fracture the clump formed about agglomeration of the litter. It isbelieved that the powder will swell when placed into contact withliquid. If the swelling is too great, the litter may clump but the clumpmay be too friable to function adequately as a clumping animal litter.Generally, the clumps should be sufficiently cohesive to enable removalon the clump from unspoiled animal litter. The exact amount of the woodpowder will depend on a number of factors, including the overallcomposition of the product and, it is believed, the particle sizedistribution of the wood powder starting material.

The animal litter may include one or more lubricants including fats,oils and mixtures thereof. The lubricant is not necessarily believed toprovide desired properties itself to the litter, but is believed to beuseful in connection with the preparation of the litter. The lubricantcan be present in any amount sufficient to facilitate the compaction ofthe animal litter composition into particles, as described herein. Forexample, in one form, the animal litter includes ground virgin corngerm. Virgin germ contains oils and used as a lubricant. The germ may beincluded in any suitable amount. A typical range of amounts will be fromabout 1% to about 10% by weight.

Other suitable lubricants include, for example, fats and oils. Exemplaryfats include lauric fats, such as babassu, coconut and palm kernel, andanimal fats, such as butter oil, chicken fat, lard and beef tallow.Exemplary oils include fish oils, such as menhaden, and vegetable oils.Preferred vegetable oils include, for example, canola, cocoa butter,corn, cottonseed, olive, palm, peanut, rapeseed, soybean and sesame.Preferably, the lubricant is a vegetable oil because animals are oftenattracted to animal fats and fish oils as a food source. When used, suchlubricant may be effect, may be used in any suitable amount, such as1-10% by weight.

The animal litter also includes at least one cohesiveness agent which isemployed to effect intraparticle cohesion. Prior art litters employmodified, pre-gelatinized starches to effect adhesion between particlesof litter, i.e., interparticle adhesion. When a polysaccharidecohesiveness agent is employed, the cohesiveness agent is believed toprovide additional hydroxyl groups, which enhance the bonding betweengrain proteins within the litter granule. It is further believed thatthe additional hydroxyl groups so function by enhancing the hydrogenbonding of proteins to starch and to other proteins. The cohesivenessagent may be present in any amount suitable to enhance the cohesivenessof the granules of animal litter.

The cohesiveness agent preferably is a polysaccharide. Any suitablepolysaccharide may be used in conjunction with the invention and thus,for example, the cohesiveness agent may comprise one or morepolysaccharides such as dextrins, maltodextrins, starches, flours,cellulosics, hemicellulosics, and the like. Preferably, the cohesivenessagent comprises a starch, and most preferably, the cohesiveness agentcomprises a corn starch. It has been found that non-gelatinized,unmodified starches are especially suitable for use as cohesivenessagents in conjunction with the invention. When unmodified starches areemployed, it is believed that such starches may contribute to a smallextent to interparticle adhesion in the clumped litter.

The cohesiveness agent may further include a fibrous material. Fibersfor use as a cohesiveness agent include soluble and insoluble fiberssuch as apple fiber, barley-bran flour, barley-flour, brewers spentgrain, carrageenan gum, citrus fiber, citrus pulp sacs, cocoa, cornbran, corn fiber, dried cranberries, fig powder, guar gum, gum agar, gumArabic, locust bean gum, oat bran, oat fiber, pea fiber, powderedcellulose, dried prunes, defatted rice bran, stabilized rice bran, ricefiber, sodium carboxymethylcellulose, soy fiber, sugar beat fiber, wheatbran, and defatted wheat germ. Other suitable fibers include, forexample, cellulose, microcrystalline cellulose, resistant starch,chitin/chitosan, methylcellulose, hydroxypropyl methylcellulose,carboxymethylcellulose, pectin, alginate, karaya, tragacanth, gellan,arabinogalactan, inulin, konjac flour, psyllium seed husk, curdlan, andpolydextrose. It is contemplated that some of these materials willfunction as sorbents in some embodiments. To the extent that acohesiveness agent is indeed in the litter formation, the cohesivenessagent is an ingredient that is different from the “sorbent.” In otherwords a litter that is said to include both a “sorbent” and a“cohesiveness agent” will have separate ingredients for the sorbent andthe cohesiveness agent, even though the cohesiveness agent may have itsown sorption properties and even though the sorbent may contain plantfiber.

The cohesiveness agent may be included in a variety of amounts. Forexample, in one form, the cohesiveness agent is included in a range ofabout 5% to about 40%. Other cohesiveness agents and amounts ofcohesiveness agents may be included as discussed in more detail below.The litter may include further includes a supplemental cohesivenessagent, which is an ionic species that is believed to enhanceprotein-protein and/or protein-starch interactions. Any suitable ionicsalt may be used in conjunction with the invention. For example, thesupplemental cohesiveness agent may be selected from among the alkaliand alkaline-earth salts of common anions, such as the halide, nitrate,nitrite, carbonate, phosphate, sulfate, and bicarbonate salts, and thelike. Exemplary supplemental cohesiveness agents include of sodiumchloride, calcium chloride, sodium carbonate, calcium carbonate, sodiumbicarbonate and mixtures thereof. The supplemental cohesiveness agentmay be present in any amount sufficient to assist the cohesiveness agentin enhancing the cohesion of the animal litter granules.

Further, the animal litters may include ingredients such as whole groundgrain, or grain meal. By “plant meal” it is meant to include meals orflours from grain, beans, grass, and the like, which are typicallythought of as agriculturally derived meals or flours. Any plant mealthat may be formulated into a clumping litter in accordance with theteachings herein may be deemed suitable for use. The plant mealpreferably is a grain meal, i.e., a ground grain, and preferably is aground whole grain. In some embodiments, ground fines can be removedfrom a whole grain meal, such as by screening. The remaining groundproduct is still deemed to be a whole grain meal within the meaning ofthe present application. Suitable plant meals include, for example, cornmeal, soy meal, sorghum meal, alfalfa meal, barley meal, and the like.Combinations of two or more of the foregoing may be used. Preferably,the grain meal used in the animal litter includes a grain meal derivedfrom an oil-rich grain. Most preferably, the grain meal is derived fromcorn grain.

For practical considerations, the grain meal preferably consists of awhole unprocessed grain meal, though a processed grain meal or acombination of a whole grain meal and a processed grain meal may also beused in the animal litter. By “whole grain meal” it is meant to includea milled whole grain, such as grain meal that is produced in a wet ordry milling process. Processed grain meal includes, for example, meal orflour from which the germ or bran has been removed. In one preferredembodiment, the grain meal used in the animal litter includes whole cornmeal or a combination of whole corn meal and processed corn meal, suchas defatted corn meal obtained from a solvent extraction or pressextraction process. In some embodiments, the litter includes the grainmeal, such as ground corn, in amounts of 40-80% by weight; in someembodiments, from 50-70% by weight; and in some embodiments, from 50-60%by weight.

In some embodiments, the litter includes a plant fiber that is effectivein enhancing the agglomeration of the particles of litter when wetted.In one form, the fiber is present in at least an amount effective toenhance the agglomeration of the particles of animal litter when theparticles are contacted with a liquid such as animal urine. Withoutbeing bound by any particular theory, it is contemplated that the fiberprovides for an enhancement of clump strength, or an increase in clumpcohesiveness, and in many embodiments, an increase in both clumpstrength and cohesiveness. The enhancement in particle agglomeration,with respect both to clump strength and cohesiveness, is believed to bedue to enhancement of adhesion between the particles, which in somecases is believed to be due to hydrogen bonding phenomena. Clumpstrength is a measure of the force required to fracture a clump ofanimal litter, while cohesiveness is a measure of the friability of aclump. A high clump strength is advantageous in that it reduces thelikelihood of breakage of the clumps, thereby allowing the soiled animallitter to be removed more effectively. High clump strength alsominimizes the likelihood of leaving behind soiled animal litter that maybreak off upon removal of soiled clumps. Both clump strength andcohesiveness, but especially cohesiveness, may be qualitativelyevaluated with the increase in these properties being evaluated relativeto an animal litter that does not include the fiber.

Any suitable plant fiber or combination of fibers may be used. Exemplaryplant fibers include grain bran and citrus residues. Preferred grainbrans include, for example, wheat bran, corn bran, soy bran, sorghumbran, barley bran, or any combination thereof. Preferably, the grainbran includes a ground corn bran. In one form, the grain bran ispreferably present in an amount of from about 1% to about 90%, morepreferably from about 3% to about 70%, even more preferably from about4% to about 50%, and most preferably from about 5% to about 30% byweight of the animal litter. These amounts are exclusive of any branpresent in the grain meal, with the proviso that the invention is notintended to encompass ground whole grain to which nothing has beenadded. If the litter is embodied in a product that comprises one or bothof grain meal or grain germ in combination with a grain bran, the grainbran being a bran from the same grain from which the meal is derived,then in preferred embodiments the bran is present in the litter in anamount greater than that in which the bran would naturally be present inground whole grain. Preferably, the bran is present in an amount of atleast 5% more than would be present in the ground whole grain; morepreferably, the bran is present in an amount of at least 10% more thanwould be so present. In some embodiments, a litter may comprise one orboth of a grain meal or grain germ in combination with a grain bran, thegrain bran being a bran from a different grain than the grain from whichthe meal or germ is derived. More generally, the germ, grain, andcohesiveness agent should be present as discrete ingredients, by whichis contemplated that the various components of the litter do notcomprise a whole ground grain, or constitute ingredients which whencombined and ground are indistinguishable from whole ground grain(although whole ground grain may be a component of the animal litter).

The plant fiber used can include a combination of fibers. In oneembodiment, the combination of fibers includes a combination of grainbran and citrus fiber. In this embodiment, the fiber can include amixture of a grain bran, citrus peels and citrus pulp. When the fiberincludes grain bran and a citrus peel/pulp combination, it is preferredthat the grain bran is present in an amount of from about 10% to about20% by weight of the litter, and the combination of citrus peel andcitrus pulp is present in an amount of from about 10% to about 20% byweight of the animal litter.

Because the animal litter is made from biodegradable materials, thelitter is subject to spoilage, such as by molding or bacterial action.To prevent or inhibit such spoilage, the litter can include a microbialinhibitor. A microbial inhibitor can be present in any amount effectiveto inhibit or prevent the spoilage of the animal litter. Typically, anyingredient capable of maintaining a pH of the animal litter from about 3to about 5.5 is effective to prevent or inhibit spoilage of the animallitter.

In one embodiment, the spoilage inhibitor is a mold inhibitor. Anysuitable mold inhibitor can be employed in conjunction with theinvention. The mold inhibitor can include, for example, sodium chloride(which can also provide supplemental cohesive properties), propionicacid, propionate salts (e.g., sodium propionate, calcium propionate andthe like), citric acid, citric acid salts (e.g., sodium citrate, calciumcitrate, potassium citrate and the like), benzoate salts (e.g., sodiumbenzoate), parabens (e.g., methylparaben, ethylparaben, propylparabenand the like), sorbic acid, and sorbic acid salts (e.g., potassiumsorbate and the like), lactic acid and lactic acid salts, acetic acidand acetic acid salts, alginic acid and alginic acid salts, and anycombination thereof.

Preferably, the mold inhibitor includes citric acid, sodium chloride,potassium sorbate, or any combination thereof. More preferably, the moldinhibitor includes a combination of citric acid, sodium chloride andpotassium sorbate or a combination of citric acid and sodium chloride.When citric acid is used, it is preferably present in an amount of about0.5% to 2% by weight of the animal litter. When sodium chloride is used,it is preferably present in the animal litter in an amount of about 2%by weight of the animal litter (sodium chloride is believed to functionas a supplemental cohesiveness agent when used in this amount). Whenpotassium sorbate is used, it is preferably present in the animal litterin an amount of from 0.1-0.5%, more preferably from 0.1-0.2%, by weightof the animal litter. Other microbial inhibitors may be included ifdesired, and such ingredients can be present in any amount suitable fortheir intended purpose.

The animal litter may also include other materials to help in odorabsorption and/or elimination. For example, the animal litter mayinclude an odor-absorbing effective amount, such as 2-5%, of acarbon-based odor-absorbing material as described in U.S. applicationSer. No. 61/600,966, filed Feb. 20, 2012 and entitled “Odor-AbsorbingMaterials And Processes For Their Preparation And Use.”

The litter may be provided with a fragrance-imparting material toprovide a pleasant scent. In one aspect, a scent is provided from anatural source, such as but not limited to alfalfa, almond, amber,angelica root, anise, apple, apricot, banana, basil, bay, bay laurel,benzoin, bergamot, bitter orange, black pepper, bois de rose (rosewood),cajeput, cardamom, carrot seed, cedarwood, cedarwood atlas, cinnamon,citronella, citrus, clary sage, clove, cocoa, coconut, coffee,coriander, cranberry, cypress, elemi, eucalyptus globulous, eucalyptus,fennel, frankincense, galbanum, geranium, German chamomile, ginger,grapefruit, helichrysum, hyssop, jasmine, juniper berry, lavender,lemon, lemongrass, lily, linden blossom, mango, marjoram, melissa, mint,myrrh, myrtle, neroli, niaouli, nutmeg, orange, oregano, palm, parsley,patchouli, peach, peppermint, petitgrain, pine, pineapple, raspberry,Roman chamomile, rose, rosemary, sandalwood, spearmint, spruce,strawberry, tea, thyme, vanilla, vetiver, violet, yarrow, ylang ylang,and the like. Plant parts that do not provide a scent or have very lowscent but that are visually appealing can also be used. The plant partscan be subjected to a process to reduce the size of the parts to a sizesuitable for addition to an animal litter.

Essential oils or other plant extracts can be used in the littersdescribed herein. Extracts can be physically obtained, such as bypressing or squeezing, or by using solvent, such as oil, organicsolvent, or water, to process plant parts. For example, orange oil canbe obtained from orange peels, and rose oil can be extracted from rosepetals using vegetable or mineral oil. Commercially-available essentialoils can also be used, if desired. By one approach, one or more plantextracts or essential oils can be blended to provide a desired scent.For example, a blend of plant extracts can be provided to give a rose,“earthy,” “spring,” “fresh,” “ocean,” or other desired scent as can bereadily formulated by a skilled person in the art.

In one aspect, the deodorizing agent may include natural or syntheticfragrances. Suitable fragrances include, for example, Modern Lavender,Lavender Fields, Natural Fresh Clean, Baby Fresh Natural, Natural AmberBalsam, Natural Sweet Amber, Natural Fresh Citrus, Natural Fresh Air,and Rose from Fragrance West, Van Nuys, Calif., Baby Fresh, Lilac,Violet, Rose, Jasmine, and Lavender from Bell Flavors & Fragrances,Inc., Northbrook, Ill., Natural Lavender, Rose Geranium, NaturalRosemary Mint, Baby Powder, and Fresh Blossoms Natural from Flavor andFragrance Specialties, Mahwah, N.J., and Lavender, Jasmine, Amber, andFresh Wave from Alpha Aromatics, Fox Chapel, Pa.

In some embodiments, the litters provided herein include colorful plantparts, such as flowers, flower buds, petals, or the like, to providevisually appealing colored particles to the litter. In one aspect, thecolorful plants parts also provide a natural scent to the litter. Inanother aspect, the colorful plant parts are provided in combinationwith a natural based fragrance, such as with a scented oil. For example,brightly colored particles made from dried flowers and petals are oftenweak in scent and the fragrance of the particles can be enhanced byinclusion of a natural or synthetic fragrance.

The litter may include a blend of essential oil formulated to havelavender scent. For example, “Natural Lavender” fragrance Item# 114B13or 112E13 made by Flavor and Fragrance Specialties, Mahwah, N.J., can besprayed onto the animal litter at the ratio of 1.6 to 3.5 pounds per tonto provide the litter with a lavender scent.

By another approach, a blend of essential oil formulated to freshblossom scent, like the “Fresh Blossoms Natural” fragrance Item# 112B17made by Flavor and Fragrance Specialties, Mahwah, N.J., can be sprayedonto the animal litter at the ratio of 1.6 to 3.5 pounds per ton toprovide the litter with a fresh flower blossom scent.

The litter may include dried lavender flowers and flower buds can beadded to the lavender or fresh blossom scented litter at a ratio of 1 to6.3 pounds per ton of litter. The dried lavender flowers and budsprovide a pleasant and sweet scent to the litter while also providingbright colored particles which are appealing to consumers. The flowersprovide the impression of a natural fresh scent even though the scent isprovided primarily from the essential oil.

In another aspect, dried global amaranth flowers and flower petals canbe added to the lavender or fresh blossom scented litter.

By another approach, no scented oils are added to the litters. Instead,dried global amaranth flowers and flower petals are added at a ratio ofabout 0.88 pounds per ton of litter and lavender flowers and buds areadded at a ratio of about 6.3 pounds per ton of litter. The globalamaranth flowers and petals have significantly brighter color than thelavender flowers and provide brightly colored particles that areappealing to consumers but are weak in scent. The dried lavender flowersand buds provide an appealing visual appearance and a pleasant and sweetscent to the litter. The colorful amaranth flowers and scent from thelavender flowers provide consumers with the impression of a natural,fresh scent.

In yet another aspect, dried “forget-me-not” flowers, rose petals,purple clover flowers, global amaranth flowers and flower petals,cornflower, cowslip, St. John's wort flowers, yarrow flowers, or fieldpoppy flowers, are added to the litter at a ratio of about 0.88 poundsto 2 pounds per ton of litter. The dried flowers and petals providebrightly colored particles that are appealing to consumers.

By one approach, the scent of the litter can be changed seasonally. Forexample, the litter can be scented to reflect each of the four seasonsof the year. For example, a coffee scent can be prepared from spentcoffee grounds. A vanilla scent can be provided from vanilla extract. Acoconut scent can be provided from coconut copra pellets. A strawberryor apple scent can be provided by addition of apple or strawberryby-products.

In some cases, the animal litter including plant parts and/or fragranceis packaged under conditions effective to lengthen the shelf life of thescented product. In one aspect, the scented litters can be packaged in aplastic bag with oxygen barrier properties, such as, for example, alaminated polyethylene and polyester or nylon plastic package. Inanother aspect, the packaging is purged with nitrogen gas to reduce theoxygen level inside the package to less than 10 percent v/v, preferablyless than 2 percent v/v. The lower oxygen content would reduce theoxidization of components of the natural fragrance, which was believedto reduce the shelf life of the natural fragrance. Under theseconditions, the shelf life of the scented litter is at least about 20weeks.

The animal litter preferably has a moisture content sufficiently high toprevent the articles of animal litter from becoming friable andsufficiently low to allow additional moisture to be absorbed.Preferably, the moisture content of the inventive animal litter is lessthan about 30% based on the weight of the litter. More preferably, themoisture content ranges from about 3% to about 25%; even morepreferably, the moisture content ranges from about 5% to about 20%; andmost preferably the moisture content is from about 8% to about 15%. Itis contemplated that some of the moisture in the animal litter will bepresent originally in the sorbent materials and/or cohesiveness agent.In some embodiments, the moisture content will be about 12% or less.

In exemplary embodiments, the animal has been found effective insuppressing odors of animal waste such as animal urine. Animal urinecontains urea, allantoin, or other compounds which break down to formammonia. The ammonia odor of spent animal litter is often considered tobe objectionable. Animal litters made in accordance with thisapplication will be effective in substantially reducing ammonia odors,and a litter box (housed or exposed) containing such litter will remainsubstantially free from ammonia odors for about 30 ours or more afterthe animal has excreted waste into the litter.

In one form, the animal litter preferably has a density sufficient toallow interparticle binding, yet that will minimize the weight of thelitter. The litter preferably has a bulk density ranging from about400-800 kg/m³. Lighter density may have a tendency to make the littertoo light and result in “tracking” by an animal, such as a cat. Densitypreferably is evaluated after loosely filling a container and measuringthe weight of a specific volume of the litter.

It will be appreciated that the particle size distribution can have aneffect on the functional properties of the animal litter. If there is arelatively high population of very large particles, the litter mayabsorb liquids more slowly and also may be less effective in maskingammonia odor or other undesirable odors of spent animal litter. On theother hand, a relatively high population of small particles or fines canresult in “tracking” and reduced clump strength. In some embodiments,the litter has the following size distribution:

% Over % Over % Over % Over % Over % Over % #8 #14 #20 #30 #40 #80 inSieve Sieve Sieve Sieve Sieve Sieve pan 8-15 55-75 10-20 <6 <3 <2 <1

Because the animal litter is to be used to absorb animal waste, e.g.,urine, the litter should have an absorption capacity sufficient to allowthe animal litter to so function. The absorption capacity of the litterpreferably is at least about 0.05 ml water per gram of litter, morepreferably ranges from about 0.5 to about 1.5 ml/g, and most preferablyranges from about 0.8 to about 1.2 ml/g. The absorption capacitiesspecified herein are determined per gram of animal litter, based on theabsorption of deionized water. Preferred absorption capacity rangesbased on the absorption of deionized water are believed to approximatethat of animal urine.

Other properties may be desired of an animal litter. For example, tominimize inconvenience and mess associated with packaging, transporting,and using the litter, the litter preferably generates a minimal amountof dust. In one form, the preferred litters do not generate substantialdust, and ordinarily do not require dust reducing agents (although suchmay be added if desired). Moreover, the preferred litters have asand-like texture that is not fluffy, which is preferred by domesticanimals such as cats.

Another preferred property is clumping efficiency. Clumping efficiencyis the amount of litter required to form a clump with a given volume ofliquid, with lower amounts of required litter corresponding to higherclumping efficiencies. Preferably, to absorb 30 ml animal urine, lessthan about 60 g of litter is required; more preferably, less than about40 g is required.

Other desired properties include biodegradability and tendency to remainclumped over time. Biodegradability is a particularly preferred propertywhen it is desired to dispose of clumps of litter by flushing them intothe toilet. The litter is believed to be at least as biodegradable asother grain-based litters, and thus the litter may be disposed of byflushing, even into a septic system. Moreover, the litter exhibitscontrolled water-absorbing capacity, making it easily flushable down atoilet without excessive expansion. This property can help avoidblockages of drain pipes, e.g., when cat owners flush the soiled litterdown the toilet. Tendency to remain clumped refers to the stability ofthe clump of the soiled litter. A clumping litter should remain clumpedfor at least 24 hours after the clump has formed. In one form, thelitters have an excellent tendency to remain clumped.

A process for preparing an animal litter is also provided. Generally,the process comprises compacting ingredients forming the animal litterinto discrete plural particles of a size suitable for use as a litter.In some embodiments, the particle size is accomplished by reducing alarger mass to the desired size. Preferably, the process includes a stepof compacting or compressing the particles of animal litter intogranules or pellets, which most preferably is accomplished in apelletizing operation. The stabilizer or mold inhibitor, cohesivenessagent, and/or lubricant, when used, can be added at any suitable stage,and preferably are mixed with the other components of the litter in thedesired proportions prior to pelletizing of the grain-based substrate.

When a pellet mill is employed, the moisture content in the pellet millfeed preferably is in the ranges described herein with respect to themoisture content in the finished product, and preferably is 10-14%.Optionally, moisture can be added to the feedstock in the form of liquidwater to bring the feedstock to the desired moisture content. Thetemperature in the pellet mill preferably is brought to about 70-90° C.,e.g., 82° C., using steam. The pellet mill may be operated under anyconditions that impart sufficient work to the feedstock to providepellets. It is believed that the particle size of the startingmaterials, the temperature within the pellet mill, and other variablescan affect the properties of the final product. The pellet mill can beoperated with a suitable die (e.g., a 3/32 in. times ⅝ in. die) at apressure and temperature effective to provide pellets. The pelletspreferably are then crumbled in a pellet mill crumbler to providediscrete plural particles having a particle size capable of passingthrough an 8 mesh screen but being retained on a 20 mesh screen orotherwise discussed above. As described herein, lubrication ispreferably provided by adding a virgin germ. In other embodiments,lubrication may be provided by adding another lubricant, such as avegetable oil.

A method for removing animal waste is also provided, which methodgenerally contemplates providing a container containing an animal litterdescribed herein, allowing an animal to excrete waste into thecontainer, whereby moisture from the waste causes the animal litter toagglomerate into at least one clump; and removing the clump of litterfrom the container and preferably any solid waste so as to remove theanimal waste. By “container” is meant to include any enclosed orpartially enclosed area, such as a litter box, a cage, a stall, a pen(such as a poultry coop), or the like. The method for the removal ofanimal waste is contemplated to be useful for all animals capable ofexcreting waste on land, such as cats, dogs, mice, birds, gerbils,reptiles, and other animals, and finds particular applicability inconnection with removal of waste from domestic house cats. The methodfor the removal of animal waste also may be useful for the removal ofwaste generated by farm animals such as chickens, livestock, or thelike.

The following examples further illustrate the invention, but should notbe construed as in any way limiting the scope of the invention.

EXAMPLES Example 1

The litter of Example 1 was prepared using a wood flour from AmericanWood Fiber, which is a pine wood powder material having 20 mesh sievesized particles. The pine wood powder material was used in the followingformulation found in Table 1.

TABLE 1 Example 1 composition. Ingredient wt % Starch (B200 or B700)* 11Pine sawdust 20-mesh 15 Citric Acid 1 Salt 3 GPC Virgin Germ 5 UltraFine Corn Bran 10 Ground Corn 54.90 Potassium Sorbate 0.10 *Availablefrom Grain Processing Corporation of Muscatine, Iowa.

The materials were mixed together and then pelletized in a pellet millwith 5/32 inch diameter holes with 2 inch VR+NVR (variable relief andnon variable relief) die at a temperature between 160-175° F. Theproduct was dried to a moisture content below 12%. The final product wasthen crumbled to reduce the size of the particles. The finished producthas a size distribution as shown in Table 2 below:

TABLE 2 Particle size distribution. % Over % Over % Over % Over % Over %Over % #8 #14 #20 #30 #40 #80 in Sieve Sieve Sieve Sieve Sieve Sieve pan8-15 55-75 10-20 <6 <3 <2 <1

The material prepared according to Example 1 formed a suitable animallitter. The product was characterized by having excellent clumpingproperties, an average clump weight of 52.7 grams when evaluated by themethods disclosed in WO03/04513482, a PCT publication of Lin Wang andThomas A. Wiesner, and assigned to Grain Processing Corporation ofMuscatine, Iowa. The product had an excellent ammonia masking propertyand formed tight solid clumps.

Example 2

A litter was prepared similarly to Example 1, but with a greater amountof pine wood powder and less corn materials than in Example 1. Theproduct was prepared by mixing the following ingredients and pelletizingusing a pellet mill with a 3/16 inch diameter holes and 2 inch variablethickness die (1⅝ inch and 2 inch thicknesses) at a temperature ofaround 180° F.

TABLE 3 Example 2 composition. Ingredient wt % Pine sawdust 20-mesh 61Corn Starch (B20F)* 30 Ground Virgin Corn Germ 4.90 Salt 3 Citric Acid 1Potassium Sorbate 0.10 *Available from Grain Processing Corporation ofMuscatine, Iowa.

The material prepared according to Example 2 formed a suitable animallitter and had a clump weight of 64 grams.

Example 3

To the litter of Example 3 is added a puffed extruded odor-absorbingmaterial prepared in accordance with U.S. Application Ser. No.61/600,966. The odor-absorbing material is added in the amount of 2% byweight. The material prepared according to Example 3 formed a suitableanimal litter.

Example 4

A litter was prepared similarly to Example 1, but with the compositionshown in Table 4 below. The materials were mixed together and thenpelletized in a pellet mill with 5/32 inch diameter holes with 2 inchVR+NVR (variable relief and non variable relief) die at a temperaturebetween 160-175° F.

TABLE 4 Example 4 composition. Ingredient wt % Starch 11.00 Pine sawdust20-mesh 14.00 Citric Acid 1.00 Salt 3.00 Virgin Germ 4.00 Ground CitrusPeel Pellet 20.00 Ground Corn 46.90 Potassium Sorbate 0.10

The material prepared according to Example 4 formed a suitable animallitter and had a clump weight of 56 grams.

Example 5

An animal litter was prepared by mixing the following ingredients andpelletizing using a pellet mill with 3/16 inch diameter holes and 2 inchvariable thickness die (1⅝ inch and 2 inch thicknesses) at a temperatureof around 180° F.

TABLE 5 Example 5 composition. Ingredient wt % Pine sawdust 20-mesh 61Corn Starch (B20F) 30 Ground Virgin Corn Germ 4.90 Salt 3 Citric Acid 1Potassium Sorbate 0.10

The material prepared according to Example 5 formed a suitable animallitter and had a clump weight of 54 grams.

Example 6

An animal litter is prepared by pelletizing the following ingredientsusing a pellet mill with 3/16″ diameter holes and 2″ variable thicknessdie (1⅝ inch and 2i inch thicknesses) at a temperature of between150-180° F.

Ingredient wt % Pine sawdust 20-mesh 25.00 Fine Ground Corn Cob 35.00(Hammer mill 1/16 screen) Corn Starch (B20F) 32.00 Ground Virgin CornGerm 4.90 Salt 2.00 Citric Acid 1.00 Potassium Sorbate 0.10

The product prepared in accordance with Example 6 formed a suitableanimal litter and had a clump weight of 52.7 grams. The productexhibited an excellent clumping property, excellent ammonia maskingproperties, and formed tight solid clumps.

Example 7

An animal litter was prepared by blending the following ingredients andpelletizing using a small pilot plant size pellet mill with 3/16 inchdiameter holes and a 2 inch variable thickness die (1⅝ inch and 2 inchthicknesses) at a temperature of around 180° F.

Ingredient wt % Pine sawdust from Wood 20-mesh 20.00 Fine Ground CornCob 42.00 (Hammer mill 1/16 screen) Corn Starch (B20F) 30.00 GroundVirgin Corn Germ 3.90 Salt 3.00 Citric Acid 1.00 Potassium Sorbate 0.10

The product formed in accordance with Example 7 formed a suitable animallitter. The product exhibited an excellent clumping property, an averageclump weight of 52.5 grams, excellent ammonia masking properties, andexhibited tight solid clumps.

Example 8

An animal litter was prepared by pelletizing the following ingredients.The materials were mixed together and then pelletized in a pellet millwith 5/32 inch diameter holes with 2 inch VR +NVR (variable relief andnon variable relief) die at a temperature between 160-175° F.:

Ingredient wt % Unmodified Corn Starch 11.9 Pine sawdust 20-mesh 14.9Citric Acid 1.0 Salt 3.0 GPC Virgin germ 7.0 Ultra Fine corn Bran 6.5Ground Corn 55.6 Potassium Sorbate 0.1The product was ground to the following particle size profile (averageover more than ten runs):

% Over % Over % Over % Over % Over % Over % #8 #14 #20 #30 #40 #80 inSieve Sieve Sieve Sieve Sieve Sieve pan 8-15 55-75 10-20 <6 <3 <2 <1

The pelletized product was suitable for uses in animal litter. Theproduct exhibited an excellent clumping property, an average clumpweight of 59.6 grams, solid clump strength, and an excellent ammoniamasking property. The loose bulk density of the product was 32.7 lb/cu.ft. and the packed bulk density of the product was 35.2 lb/cu. ft. Theproduct was deemed an excellent animal litter.

It is thus seen that animal litters may be prepared in accordance withthe foregoing teachings.

All percentages stated herein other than moisture percentages arespecified on a dry solids basis unless otherwise indicated.

All references cited and previous applications are hereby incorporatedby reference in their entireties.

Uses of singular terms such as “a,” “an,” are intended to cover both thesingular and the plural, unless otherwise indicated herein or clearlycontradicted by context. The terms “comprising,” “having,” “including,”and “containing” are to be construed as open-ended terms. Anydescription of certain embodiments as “preferred” embodiments, and otherrecitation of embodiments, features, or ranges as being preferred, orsuggestion that such are preferred, is not deemed to be limiting. Theinvention is deemed to encompass embodiments that are presently deemedto be less preferred and that may be described herein as such. Allmethods described herein can be performed in any suitable order unlessotherwise indicated herein or otherwise clearly contradicted by context.The use of any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended to illuminate the invention and does notpose a limitation on the scope of the invention. Any statement herein asto the nature or benefits of the invention or of the preferredembodiments is not intended to be limiting. This invention includes allmodifications and equivalents of the subject matter recited herein aspermitted by applicable law. Moreover, any combination of theabove-described elements in all possible variations thereof isencompassed by the invention unless otherwise indicated herein orotherwise clearly contradicted by context. The description herein of anyreference or patent, even if identified as “prior,” is not intended toconstitute a concession that such reference or patent is available asprior art against the present invention. No unclaimed language should bedeemed to limit the invention in scope. Any statements or suggestionsherein that certain features constitute a component of the claimedinvention are not intended to be limiting unless reflected in theappended claims. Neither the marking of the patent number on any productnor the identification of the patent number in connection with anyservice should be deemed a representation that all embodiments describedherein are incorporated into such product or service.

1. An animal litter comprising: a sorbent comprising at least about 10weight % finely ground pine wood powder; a lubricant; and a cohesivenessagent, the animal litter being in the form of discrete plural particleswhich tend to agglomerate when wetted, the cohesiveness agent beingpresent in an amount effective to enhance the intraparticle cohesion ofthe particles.
 2. The animal litter of claim 1 wherein the pine woodpowder is configured to pass through a 20 mesh screen.
 3. The animallitter of claim 1 wherein the lubricant is selected from the groupconsisting of corn germ, virgin corn germ, fats, oils and mixturesthereof.
 4. The animal litter of claim 1 wherein the cohesiveness agentis corn starch.
 5. The animal litter of claim 1 further comprising amold inhibitor selected from the group consisting of citric acid,potassium sorbate and mixtures thereof.
 6. The animal litter of claim 1wherein the pine wood powder is included in an amount of at least about40 weight %.
 7. A process for preparing an animal litter, the methodcomprising: providing a mixture of a sorbent comprising at least about10 weight % finely ground pine wood powder, a lubricant and acohesiveness agent; and compacting the mixture of into discrete pluralcompacted particles which tend to agglomerate when wetted.
 8. Theprocess of claim 7 wherein the pine wood powder is configured to passthrough a 20 mesh screen.
 9. The process of claim 7 wherein thelubricant is selected from the group consisting of corn germ, virgincorn germ, fats, oils and mixtures thereof.
 10. The process of claim 7wherein the cohesiveness agent is corn starch.
 11. The process of claim7 wherein the mixture further comprises a mold inhibitor selected fromthe group consisting of citric acid, potassium sorbate and mixturesthereof.
 12. The process of claim 7 wherein the mixture includes atleast about 40 weight % pine wood powder.
 13. A method for removal ofanimal waste, comprising: providing a container including an animallitter, said animal litter comprising: a sorbent comprising at leastabout 10 weight % finely ground pine wood powder; a lubricant; and acohesiveness agent, said cohesiveness agent comprising a starch; saidanimal litter being in the form of discrete plural compacted particleswhich tend to agglomerate when wetted, said cohesiveness agent beingpresent in said litter in an amount effective to enhance theintraparticle cohesion of said particles, allowing an animal to excretewaste into said litter, whereby liquid present in said container as aresult of said waste causes at least a portion of said litter toagglomerate into at least one clump; and removing said clump from saidcontainer.
 14. The method of claim 13 wherein the pine wood powder isconfigured to pass through a 20 mesh screen.
 15. The method of claim 13wherein the lubricant is selected from the group consisting of corngerm, virgin corn germ, fats, oils and mixtures thereof.
 16. The methodof claim 13 wherein the cohesiveness agent is corn starch.
 17. Themethod of claim 13 wherein the mixture further comprises a moldinhibitor selected from the group consisting of citric acid, potassiumsorbate and mixtures thereof.
 18. The method of claim 13 wherein themixture includes at least about 40 weight % pine wood powder.